This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. Primary support for the subproject and the subproject's principal investigator may have been provided by other sources, including other NIH sources. The Total Cost listed for the subproject likely represents the estimated amount of Center infrastructure utilized by the subproject, not direct funding provided by the NCRR grant to the subproject or subproject staff. Carbon nanotubes (CNT) are allotropes of carbon. They are extremely thin hollow cylinders made of carbon atoms. Unique mechanical and electrical properties of CNT make them potentially useful in many applications in nanotechnology, electronics, optics and other fields of material science. Recently, they have attracted attention as prospective drug delivery agents, especially in cancer treatment. Leaky blood vessels in tumors cause accumulation of nanoparticles introduced into the bloodstream in the cancerous tissue. Understanding incorporation of organic molecules in carbon nanotubes and delivery of the former can help in designing new drugs and treatment techniques. ACERT published a successful study on control drug release from micro-scale biodegradable microspheres. Studying drug release from nano-materials will be a further implementation of unique opportunities provided by ESR spectroscopy in general and novel technologies being developed in ACERT, such as high resolution ESR microscopy.